Prognostic Analysis Of Different Local Treatment Patterns For Internal Mammary Lymph Node Metastasis In Initially Diagnosed Breast Cancer Patients With Internal Mammary Lymph Node Metastasis

Objective: The purpose of this study was to explore the optimal pattern of local treatment and prognostic analysis for internal mammary lymph node(IMLN)metastasis in initially diagnosed breast cancer patients with internal mammary lymph node metastasis.Methods:A retrospective analysis was performed on 200 initially diagnosed female breast cancer patients with internal mammary lymph node metastasis who received radiotherapy on the chest wall and supraclavicular region from January 2010 to December 2016.The patients were divided into the intervention group(146 cases)and the non-intervention group(54 cases)according to whether the internal mammary lymph nodes metastasis of the patients took local intervention.According to different local intervention methods,the intervention group was divided into 3 groups.Among them,33 patients in the IMLN resection/excision combined with IMLN radiotherapy group(hereinafter referred to as the surgical combined with radiotherapy group),88 patients in the IMLN radiotherapy group(hereinafter referred to as the radiotherapy alone group),and 25 patients in the IMLN dissection/excision group(hereinafter referred to as the surgery alone group).To explore the effects of different local treatment patterns on 5-year localregion relapse-free survival(LRFS),Distant metastasis-free survival(DMFS),progression-free survival(PFS)and overall survival(OS).Results: The median follow-up time was 56.5 months(9.6-126.0months).Univariate analysis showed that the 5-year LRFS,DMFS,PFS,OS of the intervention group and the non-intervention group were68.50%,52.60%(P=0.008),69.00%,50.10%(P=0.009),65.60%,46.80%(P=0.004),75.10%,62.10%(P=0.032),respectively,and the differences were statistically significant.Multiariate analysis indicated that whether the internal mammary lymph nodes metastasis took local intervention or not,menstrual status,clinical T stage,the number of positive axillary lymph nodes and Ki-67 status were independent prognostic factors for the 5-year LRFS(P<0.05);whether the internal mammary lymph nodes metastasis took local intervention or not,clinical T stage and the number of positive axillary lymph nodes were independent prognostic factors for the 5-year DMFS(P<0.05);whether the internal mammary lymph nodes metastasis took local intervention or not,clinical T stage and the number of positive axillary lymph nodes were independent prognostic factors for the 5-year PFS(P<0.05);Clinical T stage and the number of positive axillary lymph nodes were independent prognostic factors for the 5-year OS(P<0.05).Subgroup analysis found that there were no statistically significant differences in LRFS,DMFS,PFS and OS in the surgical combined with radiotherapy group,the surgery alone group,and the radiotherapy alone group(P>0.05).There were no statistically significant differences in 5-year LRFS,DMFS,PFS and OS for patients with internal mammary lymph nodes metastasis reaching CR before radiotherapy(P>0.05).For those who did not reach CR before radiotherapy,the 5-year DMFS and PFS who received and did not receive radiotherapy were 63.3%,41.3%(P=0.027)and60.3%,33.3%(P=0.01),the differences were statistically significant;but there were no statistically significant differences in 5-year LRFS and OS(P>0.05).Conclusions:1.For breast cancer patients with internal mammary lymph node metastasis,IMLNs took local intervention can improve 5-year LRFS,DMFS and PFS.2.There was no statistical differences in different local treatment patterns(surgical combined with radiotherapy,the surgery alone,and the radiotherapy alone)in 5-year LRFS,DMFS,PFS and OS.3.Radiotherapy in IMLN region may improve the 5-year PFS in patients whose internal mammary lymph nodes metastasis have not reach CR before radiotherapy.4.Clinical T stage and the number of positive axillary lymph nodes were the main factors affecting the prognosis of patients.